Can I enter the USA with a naturalization certificate and foreign passport?

You cannot fly back to the US with your naturalisation certificate.

The only solution is getting an emergency passport at the US embassy in Madrid.

Are you applying for dual citizenship? Are you renouncing your Peruvian citizenship once you take the oath for US citizenship? What is the exact scenario with your citizenship. If I am understanding your question, your current passport will become null and void. If you are not a citizen of Peru, you can not travel on a Peruvian passport.

You can, however, apply for an emergency US passport. Since you are a new citizen, I do not know how long it will take. As a born-citizen, my emergency passport took less than 8 hours. You will have to go to the passport office in person, as soon as they open for the day. That may mean delaying your flight.

will my naturalization certificate can help to enter to USA

Yes if entering via land or sea border and aged 15/18 or under. See https://help.cbp.gov/s/article/Article-3618?language=en_US for more details:

Land or Sea Travel: U.S. citizens entering the United States by land or sea are required to present a valid WHTI-compliant document, which include:

• U.S. Passports
• U.S. Passport Cards
• Enhanced Driver's Licenses
• Enhanced Tribal Card (ETC)
• Trusted Traveler Cards (Global Entry*, NEXUS, SENTRI, or FAST
• Military Identification Cards (for members of the U.S. armed official maritime business)

* The Global Entry (GE) card is only an ENTRY document and may not be used to enter Canada, Mexico or Adjacent Island.

Military personnel traveling under orders may present photo ID and orders. Family members must present a passport (with the exception of children 15 and younger arriving by land or sea.)

Children: U.S. citizen children ages 15 and under arriving by land or sea from a contiguous territory (Canada or Mexico) may present an original or copy of his or her birth certificate (issued by the Vital Records Department in the state where he or she was born), a Consular Report of Birth Abroad, or a Naturalization Certificate. If the child is a newborn and the actual birth certificate has not arrived from the Vital Records Department, we will accept a Hospital issued birth certificate.

Groups of Children: A U.S. citizen children between the ages of 16-18 arriving by land or sea from contiguous territory and traveling with an adult supervised school group, religious group, social or cultural organization, or sports team, may also present an original or copy of his or her birth certificate, a Consular Report of Birth Abroad, or a Naturalization Certificate.

For more specific information regarding passport documents, please contact the National Passport Information Center.

For documentation requirements regarding cruises, please see our FAQ on "What Documents do I need for Cruises "

I'm guessing the certificate of naturalization also helps if you're over 18 and end up in secondary at the land border due to lack of accepted documents (US passport, Enhanced Driver's License, Global Entry, etc.), but that'd be great if someone could confirm.

FYI: What's the legal consequence of leaving the United States without using one's U.S. passport?